<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        div{
            width: 200px;
            height: 200px;
            border: 3px solid red;
            /*圆角 值越大越圆  当值超过宽高一半时为正圆*/
            /*border-radius: 150px;*/
            padding-left: 50px;
            padding-top: 50px;

        }
    </style>
</head>
<body>
<div align="center">测试边框</div>
</body>
</html>